The present invention relates generally to apparatus and methods for producing waveforms of musical tones, voices or other sounds on the basis of waveform data supplied from memory or the like, and more particularly to an improved waveform producing apparatus and method capable of producing waveforms that faithfully represent tone color variations effected by a player using various styles of rendition (i.e., performing techniques) or various sorts of articulation unique to a natural musical instrument. It should be appreciated that the basic principles of the present invention can be applied extensively to every type of equipment, apparatus and methods having the function of generating musical tones, voices or any other sounds, such as automatic performance devices, computers, electronic game devices and multimedia-related devices, not to mention electronic musical instruments. Also, let it be assumed that the terms xe2x80x9ctone waveformxe2x80x9d in this specification are not necessarily limited to a waveform of a musical tone alone and are used in a much broader sense that may embrace a waveform of a voice or any other type of sound.
The so-called xe2x80x9cwaveform memory readoutxe2x80x9d technique has already been well known, which prestores waveform data (i.e., waveform sample data) coded in a given coding scheme, such as the PCM (Pulse Code Modulation), DPCM (Differential Pulse Code Modulation) or ADPCM (Adaptive Differential Pulse Code Modulation), and then reads out the thus-prestored waveform data at a rate corresponding to a desired tone pitch to thereby produce a tone waveform. So far, various types of xe2x80x9cwaveform memory readoutxe2x80x9d technique have been proposed and known in the art, most of which are directed to producing a waveform covering from the start to end of a tone. As one specific example of the waveform memory readout technique, there has been known a scheme of prestoring waveform data of a complete waveform of a tone covering from the start to end thereof. As another example of the waveform memory readout technique, there has been known a scheme of prestoring waveform data of a complete waveform only for a particular portion, such as an attach portion, of a tone presenting relatively complex variations and prestoring a predetermined loop waveform for a sustain portion and the like presenting less variations. In this patent specification, the terms xe2x80x9cloop waveformxe2x80x9d are used to refer to a waveform to be read out repeatedly, i.e., in a looped fashion.
With the conventional waveform memory readout scheme of prestoring waveform data of a complete waveform of a tone covering from the start to end thereof or prestoring waveform data of a complete waveform only for a particular portion, such as an attach portion, of a tone, however, it has been necessary to prestore a great number of various waveform data corresponding to a variety of styles of rendition (or various sorts of articulation), which would undesirably require a large storage capacity.
Further, although the above-mentioned scheme of prestoring waveform data of a complete waveform of a tone can faithfully express tone color variations effected using various styles of rendition (or various sorts of articulation) unique to a natural musical instrument, it can only reproduce the tone in just the same way as the prestored waveform data and thus would afford very poor controllability and editability. For instance, with this waveform memory readout scheme, it has been extremely difficult to control time-axial and other characteristics of the waveform data, corresponding to a desired style of rendition (or sort of articulation), in accordance with performance data.
It is therefore an object of the present invention to provide a waveform producing technique which can produce high-quality waveform data corresponding to a variety of styles of rendition (or various sorts of articulation) in a simplified manner with greatly increased facility and controllability. Particularly, the present invention seeks to provide a waveform producing method and apparatus which can control characteristics of sample data to be used for the waveform production in a simplified manner with enhanced controllability, by performing necessary adjustment or modification of the sample data on the basis of a representative sample point designated or identified from among the sample data.
In order to accomplish the above-mentioned object, the present invention provides a waveform recording method which comprises the steps of: receiving sample identification information and representative-point designating data; obtaining sample data by referring to a database in accordance with the received sample identification information; adjusting the obtained sample data on the basis of the received representative-point designating data, when the obtained sample data is to be adjusted; and producing a waveform on the basis of the obtained sample data or the adjusted sample data. The sample data comprises sampled data at a plurality of sample points constituting a given waveform (which may be of any type such as a tone color waveform or envelope waveform). The representative-point designating data is data designating or identifying, as one or more representative points, one or more of the plurality of sample points in the sample data. The designated representative (sample) points may be dispersed points or successive points within a given range, or may be dispersed across separate ranges. When the sample data is to be adjusted, modified or changed, it is adjusted on the basis of the representative points designated by the representative-point designating data. Characteristics of individual sample data can be controlled appropriately and efficiently by the representative-point designating data specifying representative sample points for which the sample data adjustment is to be performed, so that characteristics of the waveform to be produced can be controlled in accordance with the respective characteristics of the individual sample data in a simplified manner with enhanced controllability.
The sample data adjustment based on the representative-point designating data may be performed in any appropriate manner. For example, particular sample data at a representative sample point designated by the representative-point designating data may be adjusted in accordance with given adjustment information, and other sample data at another sample point may be adjusted simultaneously with or in response to the adjustment at the representative sample point. Alternatively, simultaneously with or in response to the adjustment at the representative sample point, sample data at all of the sample points may be restored or rebuilt on the basis of the adjustment at the representative sample point. In another alternative, only particular sample data that is located at a representative sample point designated by the representative-point designating data may be adjusted without the sample data at the other sample points being adjusted at all.
The present invention also provides a waveform producing method which comprises the steps of: receiving performance data; generating sample identification information and representative-point designating data on the basis of the performance data received by the step of receiving; obtaining sample data by referring to a database in accordance with the sample identification information generated by the step of generating; adjusting the obtained sample data on the basis of the representative-point designating data received by the step of receiving, when the obtained sample data is to be adjusted; and producing a waveform on the basis of the obtained sample data or the sample data adjusted by the step of adjusting. In this case, the sample identification information and representative-point designating data is given on the basis of the received performance data.
As an example, the waveform produced by the above-mentioned step of producing comprises characteristic waveform data (envelope waveform data) to be used for controlling variations over time of tone characteristics. Such characteristic waveform data (envelope waveform data) is suitable for characteristics control based on the representative point. However, the present invention is not so limited, and the waveform produced by the step of producing may be a final form of tone waveform, which, in preferred embodiments to be described later, is synthesized by a combination of a plurality of waveform factors such as a waveform shape, amplitude and pitch. The sample data employed in the present invention may be sampled data of at least one of the waveform factors. In the later-described embodiments, the sample data of these waveform factors are also referred to as vector data; that is, xe2x80x9cvectorsxe2x80x9d correspond to various fundamental waveform factors for producing a waveform. Examples of the fundamental waveform factors include a waveform shape (that determines a tone color or timbre), pitch variation over time (pitch envelope waveform) and amplitude variation over time (amplitude envelope waveform), and the vector data of these waveform factors are called a waveform shape vector, pitch vector and amplitude vector, respectively. Time vector for performing stretch/compression control on a time-axial progression of the waveform may also be used. The respective time axes of the waveform shape vector, pitch vector, amplitude vector, etc. can be controlled in accordance with the time vector.
In the later-described embodiments, the performance data are supplied in a form containing style-of-rendition identification (ID) information. For example, the style-of-rendition identification (ID) information may be supplied, according to the characteristics of styles of rendition of the performance tone, in correspondence with a partial tone segment such as an attack, body or release portion, or in correspondence with a link or joint segment between adjoining tones such as a slur, or in correspondence with a specially performed tone segment such as a vibrato, or in correspondence with a plurality of notes constituting a phrase. Namely, given style-of-rendition identification (ID) information is supplied in accordance with a performance to be reproduced.
The present invention may be constructed and implemented not only as the method invention as discussed above but also as an apparatus invention. Also, the present invention may be arranged and implemented as a software program for execution by a processor such as a computer or DSP, as well as a storage medium storing such a program. Furthermore, the processor used in the present invention may comprise a dedicated processor based on predetermined fixed hardware circuitry, rather than a general-purpose type processor capable of running software.